Balers for producing parallelepiped bales in their baling chambers, so-called square balers, are equipped with knotter tables including a plurality of knotter assemblies for respectively tying a plurality of twine loops about finished bales formed in bale chambers of the balers. Associated with each knotter assembly for aiding in the tying function is a tucker or twine finger mounted as part of the knotter table to the top of the baling chamber so as to be adjacent to a longitudinally extending slot provided for permitting a twine-carrying needle to pass through the slot and deliver twine to an associated knotter assembly during a tying cycle. Each tucker finger is mounted for pivoting between a standby position located to one side of the slot and a working position extending across the slot.
The tucker fingers of a given baler are simultaneously driven in timed relationship to the knotter assemblies by means of respective length-adjustable motion transfer links connected between crank arms that are fixed along the length of a transverse tucker finger control shaft to which oscillating motion is imparted in a timed relationship to the knotter function of the baler by an arm carrying a cam follower roller engaged with a tucker finger control cam plate, mounted for rotating together with a transverse knotter gear drive shaft.
In order for each tucker finger to operate properly, it is adjusted to its standby position by adjusting the length of the tucker finger motion transfer link when the cam follower roller is in contact with an inner radius of the cam plate. Because this setting of the tucker finger is not straight forward, errors in adjusting the tucker finger have occurred because the cam follower roller is engaged with a cam radius greater than the inner most radius, this misadjustment resulting in the associated tucker finger motion transfer link traveling over-center during a tying cycle and consequently resulting in damage to the linkage components.
What is needed then is a solution which will permit errors in adjusting a tucker finger while avoiding damage due to such adjustment errors.